Ether synthesis

A mixture of (R)-[5-(3-chloro-4-fluoro-benzenesulfonylamino)-5,6,7,8-tetrahydro- naphthalen-1-yloxy]-acetic acid tert-butyl ester (100 mg, 0.21 mmol), sodium hydride (60% dispersed in mineral oil, 50 mg, 1.25 mmol) and 4-chlorophenol (315 mg, 2.45 mmol) in N,N-dimethylformamide (2 ml) was heated in a microwave oven at 130°C for 15 minutes. The resulting mixture was then acidified with 0.1 N hydrochloric acid to pH 5. The precipitate was collected by filtration and purified by preparative HPLC to afford (R)-{5-[3-chloro-4-(4-chloro-phenoxy)-benzenesulfonylamino]-5, 6,7,8- tetrahydro-naphthalen-1-yloxy}-acetic acid terf-butyl ester (87.2 mg, 72%) as a white powder.


Patent reference: WO2010018113 (Roche)